9.23.6.1.Anchorage of Building Frames

(1) Except as required by Sentence 9.23.6.3.(1), building frames shall be anchored to the foundation unless a structural analysis that considers wind and earthquake loads and lateral earth pressures shows that anchorage is not required (2) Except as provided in Sentences (3) to (6), anchorage shall be provided by (a) embedding the ends of the first floor joists in concrete, or (b) fastening the sill plate to the foundation with not less than 12.7 mm diam anchor bolts spaced not more than 2.4 m o.c. (3) For buildings with 2 or more floors supported by frame walls that are in areas where the seismic spectral acceleration, Sa(0.2), is not greater than 0.70 or the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.80 kPa but not greater than 1.20 kPa, anchorage shall be provided by fastening the sill plate to the foundation with not less than two anchor bolts per braced wall panel, where all anchor bolts used are (a) not less than 15.9 mm in diameter, located within 0.5 m of the end of the foundation, and spaced not more than 2.4 m o.c, or (b) not less than 12.7 mm in diameter, located within 0.5 m of the end of the foundation, and spaced not more than 1.7 m o.c. (4) For buildings supported by frame walls that are in areas where the seismic spectral acceleration, S a(0.2), is greater than 0.70 but not greater than 1.8 and the 1-in-50 hourly wind pressure (HWP) is not greater than 1.20 kPa, anchorage shall be provided by fastening the sill plate to the foundation with not less than two anchor bolts per braced wall panel located within 0.5 m of the end of the foundation and spaced in accordance with Table 9.23.6.1. (5) Anchor bolts referred to in Sentences (2) to (4) shall be (a) fastened to the sill plate with nuts and washers, (b) embedded not less than 100 mm in the foundation, and (c) so designed that they may be tightened without withdrawing them from the foundation. Table 9.23.6.1. Anchor Bolt Spacing where the 1-in-50 HWP ≤ 1.20 kPa and 0.70 < Sa(0.2) ≤ 1.8 Forming Part of Sentence 9.23.6.1.(4) Maximum Spacing of Anchor Bolts Along Braced Wall Band, m Anchor Bolt Light Construction Heavy Construction(1) Sa(0.2) Diameter, mm Number of Floors Supported(2) 1 2 3 1 2 0.70 < Sa(0.2) ≤ 0.80 2.4 2.3 1.8 2.4 2.0 0.80 < Sa(0.2) ≤ 0.90 2.4 2.3 1.8 2.4 2.0 0.90 < Sa(0.2) ≤ 1.0 2.4 2.2 1.5 2.4 1.8 1.0 < Sa(0.2) ≤ 1.1 2.4 2.1 1.4 2.4 1.6 12.7 1.1 < Sa(0.2) ≤ 1.2 2.4 2.0 1.3 2.4 1.5 1.2 < Sa(0.2) ≤ 1.3 2.4 1.9 1.3 2.4 1.5 1.3 < Sa(0.2) ≤ 1.35 2.4 1.8 1.2 2.3 1.4 1.35 < Sa(0.2) ≤ 1.8 2.4 1.8 1.1 2.3 1.4 0.70 < Sa(0.2) ≤ 0.80 2.4 2.4 2.2 2.4 2.4 0.80 < Sa(0.2) ≤ 0.90 2.4 2.4 2.2 2.4 2.4 0.90 < Sa(0.2) ≤ 1.0 2.4 2.4 2.1 2.4 2.3 1.0 < Sa(0.2) ≤ 1.1 2.4 2.4 1.9 2.4 2.3 15.9 1.1 < Sa(0.2) ≤ 1.2 2.4 2.4 1.9 2.4 2.2 1.2 < Sa(0.2) ≤ 1.3 2.4 2.4 1.8 2.4 2.1 1.3 < Sa(0.2) ≤ 1.35 2.4 2.3 1.7 2.4 2.0 1.35 < Sa(0.2) ≤ 1.8 2.4 2.2 1.6 2.4 1.9 Notes to Table 9.23.6.1.: (1) See Note A-9.23.13.2.(1)(a)(i). (2) All constructions include support of a roof load in addition to the indicated number of floors. (6) Where the seismic spectral acceleration, Sa(0.2), is greater than 1.8 or the 1-in-50 hourly wind pressure is equal to or greater than 1.2 kPa, anchorage shall be designed according to Part 4.